OBD1 4.0 AT PCM interchangibility?

I have a '92 4.0 AT with some wiring problems related to the TPS. My mechanic suspects that the PCM is bad too. I am having the wiring fixed, then we'll see, but...are any of the 91-94 HO PCMs interchangable? They have different parts numbers year to year, but does that really mean anything? Why wouldn't a '93 'puter work on my '92? Just trying to broaden the parts source. A friend has a '93 or '94 that I can "borrow" when he is not looking.

Any '91-'95 computer will do as long as it comes off another XJ with an automatic tranny.

Thanks, Doc.